Introduction: The Healthy Immigrant Effect refers to the phenomenon that recent immigrants are on average healthier than their native-born counterparts. Greater immigrant acculturation to the US has been linked to increased risk of cardiovascular disease (CVD), frequently attributed to factors including the adoption of Western diets and decreased physical activity. While immigrants may have healthier habits than US adults, which may confer protection from CVD, there is little research on sleep health, particularly in immigrant women. Hypothesis: We hypothesized that immigrants, particularly those with greater acculturation, would have more sleep problems. Methods: Baseline data from a 1-y, community-based cohort of 506 women (61% racial/ethnic minority, mean age=37±16y) was used to evaluate cross-sectional associations between acculturation and sleep. Women self-reported their immigration status and national origin. Acculturation was measured from responses to questions regarding language preference, nativity (sorted by regions: Asia, Caribbean, Latin America, other), length of residency in the US, and age at immigration. Sleep duration, sleep quality, risk of obstructive sleep apnea (OSA) and insomnia were assessed using validated questionnaires. Logistic regression models adjusted for age, health insurance, education and BMI were used to evaluate associations between acculturation measures and sleep characteristics. Results: Women who were immigrants (n=176) reported lower mean sleep duration (6.60 ± 1.25 vs. 6.85 ± 1.22 h, p=0.02) compared to non-immigrants (n=323); non-immigrants were more likely than immigrants to sleep ≥7h/night (OR: 1.50, CI: 1.01-2.22, p=0.04). Women who immigrated to the US before vs. after age 25 y had lower odds of having sleep onset latency ≥26 min (OR:0.97, CI:0.95-1.00, p=0.03). Immigrant women living in the US >10y vs. <10y had more than 2-fold higher odds of having longer sleep onset latency (≥26 min) (OR:2.43, CI:1.09-5.41, p=0.03). Immigrants from the Caribbean were more likely than immigrants from other regions to be at a high risk for OSA (OR:2.65, CI:1.07-6.55, p=0.04). Conclusions: Compared to non-immigrants, immigrant women exhibit shorter habitual sleep duration. Sleep problems may vary by age of immigration, years lived in the US, and region of origin, as those who immigrated when they were older and those who had lived in the US>10 y required more time to fall asleep and Caribbean immigrants had higher OSA risk.